1. Field of the Invention
This invention relates to a tamper evident closure, and more specifically, it relates to a closure having a resin applied to the exterior thereof which will not only indicate if tampering has occurred, but will also indicate whether the tamper evident resin was in fact applied to the product by the manufacturer.
2. Description of the Prior Art
The tampering with and adulteration of many commercially available products have become critical problems endangering health and destroying purity of many products. Many products which are adulterated or tampered with ultimately reach a consumer bearing no visible indication that such adulteration or tampering has occurred. Accordingly, it is highly desirable to provide a type of packaging that will provide an indication that there has been interference with the integrity of the product packaging.
Various types of mechanical indicators used to determine the integrity of several types of products and containers are known.
U.S. Pat. No. 3,662,915 relates to a tamperproof package which provides a recessed tab in the inner periphery of a container which breaks away from the remainder of the container when entry is made into the container. This serves to indicate that tampering with the package has occurred.
U.S. Pat. No. 2,131,774 discloses a closure having a sealing liner. A disc of fibrous material is placed between the closure and the sealing liner. When the closure is removed, the disc will rupture the closing liner. See also, U.S. Pat. Nos. 4,576,297 and 4,747,499.
It has been known to provide for rupturing of outer coatings which fracture responsive to operation of a container tear strip. See U.S. Pat. No. 3,415,402. See also U.S. Pat. No. 4,479,585.
U.S. Pat. No. 4,749,084 discloses a tamper-indicating package having a web formed from two coextensive webs. Each web contains an outer layer, an inner sealable layer and an intermediate layer comprising filaments. The filaments are disposed in a random manner, thus, each package has its own unique "fingerprint". In use, the sender of the package can prepare an image of the package and send this image to the recipient of the package. In order to determine whether the package has been tampered with, the recipient can compare the images prepared by the sender with the arrangements of the filaments in the package.
My earlier U.S. Pat. Application Ser. No. 07/209,822 filed June 22, 1988, the disclosure of which is expressly incorporated herein by reference, discloses a tamper resistant package and a method of making the same. An outer protective layer of an epoxide resin is placed on a package and is subsequently cured by ultraviolet radiation. This causes the outer layer to become extremely brittle such that any physical penetration of the outer layer will cause the entire outer layer to fracture. Such fracturing will provide a clear visual indication that penetration of the outer layer has occurred as by cracking of the material and separation of the pieces from the package.
In spite of the existing prior art techniques, there remains a need for an effective method of indicating that a closure has been tampered with or adulterated. There also remains a need for a closure to indicate whether or not the tamperproofing means has been placed on the closure by the manufacturer.